Interpretive Summary: Campylobacter is a foodborne pathogen associated with poultry. Little is known about the level and persistence of this organism inside the birds organs. In this study, we found that Campylobacter travels to different immune organs inside the bird. The rapid movement of Campylobacter to internal organs following different routes of inoculation may be significant; particularly if they persist in these organs as reservoirs throughout the 65 week life cycle of breeding birds and as such play a role in the egg transmission of this human pathogen.

Technical Abstract:
Day-old broiler chicks were obtained from a commercial hatchery and inoculated (n=30), either orally or intracloacally with a characterized strain of Campylobacter jejuni. At one-hour, one-day and one-week post inoculation, broilers (n=5) from the oral and intracloacal-inoculated groups along with control birds (n=4) were humanely sacrificed by cervical dislocation. The broilers from the control and treatment groups were aseptically opened and the thymus, spleen, liver/gallbladder, bursa of Fabricius and ceca were aseptically removed and individually analyzed for Campylobacter jejuni. Overall, Campylobacter jejuni was isolated after oral inoculation from 13% (10/75), 17% (13/75) and 28% (14/50) of the one-hour, one-day and one-week samples, respectively. Campylobacter jejuni was isolated from 10% (4/40), 8% (3/40), 10% (4/40), 25% (10/40) and 40% (16/40) of the thymus, spleen, liver/gall bladder, bursa of Fabricius and ceca samples, respectively. Following the intracloacal route of inoculation, Campylobacter jejuni was recovered from 32% (24/75), 8% (6/75) and 16% (8/50) of the one-hour, one-day, and one-week samples, respectively. Campylobacter jejuni was isolated from 5% (2/40), 5% (2/40), 5% (2/40), 45% (18/40) and 40% (16/40) of the thymus, spleen, liver/gall bladder, bursa of Fabricius and ceca samples, respectively for all sampling periods. Campylobacter spp. were not recovered from sample sites examined from the control broilers from repetitions one, two or from repetitions three samples examined after one hour and one day. However, one control sample was positive from one week sampling from repetition three and therefore those data were omitted. The rapid movement of Campylobacter to internal organs following both oral and intracloacal inoculation may be significant; particularly if they persist in these organs as reservoirs throughout the 65-week life cycle of breeding birds.